# CVE-2026-90407: wifi: ath11k: fix overreads in ath11k_wmi_process_csa_switch_count_event()

> An out-of-bounds read in the ath11k Wi-Fi driver allows attackers to disclose memory or cause a system crash via crafted firmware events.

- **Severity:** High 7.7 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 17 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-102663, BELL-CVE-2026-90407, DEBIAN-CVE-2026-90407, GHSA-hhm8-7qmw-pmj8, UBUNTU-CVE-2026-90407

## What is CVE-2026-90407?

CVE-2026-90407 is a high-severity memory corruption vulnerability in Linux, published on 17 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

wifi: ath11k: fix overreads in ath11k_wmi_process_csa_switch_count_event()

There is no policy entry for WMI_TAG_PDEV_CSA_SWITCH_COUNT_STATUS_EVENT, so
the parse infrastructure does not enforce a minimum length for the event
struct. Additionally, the num_vdevs field is taken directly from firmware
and used as a loop bound over the vdev_ids array without checking that it
fits within the TLV payload. Either condition can cause an out-of-bounds
read.

Add a TLV policy entry for WMI_TAG_PDEV_CSA_SWITCH_COUNT_STATUS_EVENT so
the parse infrastructure enforces a minimum length for the fixed-size event
struct. Add a helper ath11k_wmi_tlv_data_len() to recover the payload
length of a parsed TLV from the header preceding its data pointer. Use it
in ath11k_wmi_process_csa_switch_count_event() to bound num_vdevs before
the loop.

Compile tested only.

## Which versions are affected by CVE-2026-90407?


## How do I fix CVE-2026-90407?

Apply the vendor's patch.

## Is CVE-2026-90407 being exploited?

There is no known exploitation of CVE-2026-90407 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-90407 and fix it if it is affected.

What it is: CVE-2026-90407 is a high-severity memory corruption vulnerability in Linux, published on 17 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-90407 in the wild and no public exploit code.

Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-90407/ (Markdown: https://insights.sbomify.com/CVE-2026-90407/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-90407
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-90407
- OSV: https://osv.dev/vulnerability/CVE-2026-90407

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-90407/
Summaries are generated and may contain mistakes; the official description above is the record.